Are Travel Bans the Answer to Stopping the Spread of COVID-19 Variants? Lessons from a Multi-Country SIR Model

TL;DR

This study uses a multi-country SIR model to evaluate the effectiveness of travel bans in controlling the spread of COVID-19 variants, highlighting their limited impact when variants are already widespread.

Contribution

It introduces a multi-country SIR model to simulate variant spread and assess travel ban effectiveness across European countries.

Findings

Travel bans have limited effectiveness once variants are widespread.

Unilateral bans are less effective than multilateral approaches.

Model simulations highlight the importance of early interventions.

Abstract

Detections of mutations of the SARS-CoV-2 virus gave rise to new packages of interventions. Among them, international travel restrictions have been one of the fastest and most visible responses to limit the spread of the variants. While inducing large economic losses, the epidemiological consequences of such travel restrictions are highly uncertain. They may be poorly effective when the new highly transmissible strain of the virus already circulates in many regions. Assessing the effectiveness of travel bans is difficult given the paucity of data on daily cross-border mobility and on existing variant circulation. The question is topical and timely as the new omicron variant -- classified as a variant of concern by WHO -- has been detected in Southern Africa, and perceived as (potentially) more contagious than previous strains. In this study, we develop a multi-country compartmental model of the SIR type. We use it to simulate the spread of a new variant across European countries, and to assess the effectiveness of unilateral and multilateral travel bans.